AvLaw - Which is the correct method of finding moles of gases?

In summary, the gas in the tank contains 1000 liters of methane, which is equal to 88.5 kilograms. Based on Avogadro's law, 55517.4 grams of methane are in the tank.
  • #1
axer
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4

Homework Statement


Based on your understanding of Avogadro's law.
1000 L steel storage tank contains 88.5 kg of methane gas, CH4.
Calculate no. of moles.

The Attempt at a Solution


one method= no. of moles=mass/molar mass.
no. of moles= 88500/16.04= 5517.4 moles.other method= 1 mol= 22.4 liter.
no of moles= 1000 L/22.4L= 44.6 moles.

Please inform me of the correct method, thanks!
 
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  • #2
The 22.4 L for one mole is only at S.T.P.=Standard temperature and pressure. They did not specify the temperature, but the much bigger factor here is the gas in the container is undoubtedly pressured. Assuming it is at standard temperature (zero degrees Centigrade), you could compute the pressure in atmospheres by taking the ratio of your first answer divided by your second (incorrect answer).
 
  • #3
Charles Link said:
The 22.4 L for one mole is only at S.T.P.=Standard temperature and pressure. They did not specify the temperature, but the much bigger factor here is the gas in the container is undoubtedly pressured. Assuming it is at standard temperature (zero degrees Centigrade), you could compute the pressure in atmospheres by taking the ratio of your first answer divided by your second (incorrect answer).
So 5517.4 moles is the correct number of moles? since they didn't specify the temp.
 
  • #4
axer said:
So 5517.4 moles is the correct number of moles? since they didn't specify the temp.
Yes, it is correct, regardless of the temperature. Upon being given the temperature, it would also be possible to compute the pressure. You would find that the gas is highly pressurized, unless it is being kept at very low temperature.
 
  • #5
Charles Link said:
Yes, it is correct, regardless of the temperature. Upon being given the temperature, it would also be possible to compute the pressure. You would find that the gas is highly pressurized, unless it is being kept at very low temperature.
Oh by using the ideal gas law, ok thanks!
 
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  • #6
Your first answer was correct. How could you doubt it?
In this and other questions you have shown yourself to have some grasp but were easily distracted and confused by irrelevancies. Things that were related to a question but made you miss a point.
So having been partially successful and activated it is a good time, I recommend, to go back and do some revision in order to get the concepts fixed securely in your mind. :smile:
 
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1. How do you determine the number of moles of a gas?

The correct method of finding moles of gases is by using the ideal gas law, which is PV=nRT. This equation relates the pressure (P), volume (V), temperature (T), and number of moles (n) of a gas.

2. What is the ideal gas law?

The ideal gas law is an equation that describes the relationship between the pressure, volume, temperature, and number of moles of a gas. It is written as PV=nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.

3. How do you find the number of moles of a gas at STP?

At Standard Temperature and Pressure (STP), the temperature is 273.15 K and the pressure is 1 atm. To find the number of moles of a gas at STP, you can use the equation n = PV/RT, where P is the pressure, V is the volume, R is the ideal gas constant (0.0821 L·atm/mol·K), and T is the temperature in Kelvin.

4. Can the ideal gas law be used for all gases?

The ideal gas law is a good approximation for most gases at standard temperature and pressure. However, it becomes less accurate at high pressures and low temperatures. Additionally, it does not take into account intermolecular forces, so it may not be accurate for gases with strong intermolecular forces.

5. How do you convert moles of a gas to mass?

To convert moles of a gas to mass, you need to know the molar mass of the gas. This can be found by adding up the atomic masses of the elements in the gas. Then, you can use the equation m = nM, where m is the mass, n is the number of moles, and M is the molar mass. This will give you the mass of the gas in grams.

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